Sciatica is a condition that occurs when the sciatic nerve that runs from the lower back down the length of the back of each leg becomes compressed, causing a shooting pain, numbness, tingling, or other types of discomfort anywhere in the legs, buttocks, hips, or lower back. Sciatica and back pain often go hand in hand because the nerve can cause pain in the lower back, and the pain in the lower back may also be causing the sciatica. A herniated disc, for example, can cause sciatica and back pain; the herniated disc can compress the sciatic nerve, causing sciatica, and it can cause pain in the lower back due to the sciatica or due to muscle strain or tension.
A herniated disc that causes sciatica and back pain occurs when a spinal disc — a sac filled with gel-like fluid that sits between two vertebrae — ruptures, allowing the fluid or the disc wall to press against the nerves in the spine. When the spinal disc presses against the sciatic nerve, sciatica and back pain are both likely to occur. Sciatica is often felt in the legs, hips, buttocks, and lower back, and the pain manifests itself as a sharp pain, a shooting pain, numbness, weakness, and limited mobility. The herniated disc can cause back pain in the region of the back that was herniated; when sciatic pain is felt, that region is very often the lower back.
Sciatica and back pain are not always caused by disc herniation, however. Tight or strained muscles can also cause both sciatica and back pain. As muscles tire, they tighten, and this tightening can lead to compression on the sciatic nerve. Once the sciatic nerve becomes compressed, sciatic nerve pain can radiate down the legs or into the lower back. The tight muscles of the back that are the cause of the sciatic pain can cause other types of pain as well; muscle tightness can lead to muscle strains, or tears in the tiny fibers that make up a muscle.
Regardless of whether the pain is caused by a herniated disc or by a strained or tight muscle, rest is a key component of treatment. Icing the affected region can also help alleviate the pain and keep swelling at bay. Light stretching and regular exercise will help prevent further injuries both to the muscles and to the discs in the spine; a strong muscle is less likely to tighten up and become injured, and strong back muscles will do a better job of supporting the spine and preventing herniated discs.